Logging

Mountaineer bundles a mountaineer.logging module for service-level logs. To adjust the verbosity of Mountaineer's logs, set the MOUNTAINEER_LOG_LEVEL environment variable.

MOUNTAINEER_LOG_LEVEL=WARN mountaineer runserver

We also provide some helper functions to use our same logging convention in your own code. We optimize for structured logging, where your logs are outputted as a stream of JSON-line formatted logs so they can be quickly parsed by bash pipes or by logging aggregation tools.

FUNCTIONmountaineer.logging.setup_logger

setup_logger

Constructor for the main logger used by Mountaineer and optionally for client applications as well. Provided convenient defaults for log level and formatting, alongside coloring of stdout/stderr messages and JSON fields for structured parsing.

Logs are formatted one per line:

Code
{"level": "INFO", "name": "myapp.logging", "timestamp": "2025-02-25 20:40:35,896", "message": "Application started"}

To grep over these logs and filter for level, do:

Code
# Filter for specific log level
grep '"level": "ERROR"' logfile.txt

# Filter logs by service name
grep '"name": "myapp.logging"' logfile.txt

# With jq for more advanced JSON parsing
cat logfile.txt | jq 'select(.level=="ERROR" or .level=="WARNING")'

# Filter by message content
grep -E '"message": ".*database.*"' logfile.txt

Parameters

  • Name
    name
    Type
    Description

    The name of the logger, typically the module name

  • Name
    log_level
    Type
    Description

    Default: logging.DEBUG

    The logging level. Defaults to logging.DEBUG to log everything.

Code
from mountaineer.logging import setup_logger
import logging

# Create a logger for your module
logger = setup_logger(__name__, log_level=logging.INFO)

# Use the logger
logger.info("Application started")
logger.warning("Configuration incomplete")
logger.error("Failed to connect to database")
FUNCTIONmountaineer.logging.log_time_duration

log_time_duration

Context manager to time a code block at runtime.

Code
with log_time_duration("Long computation"):
    # Simulate work
    sleep(10)

Parameters

  • Name
    message
    Type
    str
    Description